Documentation shows incorrect way to change scenes in a multiplayer game

**Your Godot version:**
4.3-stable

**Issue description:**
The latest documentation on how to use the high level multiplayer feature recommends using `get_tree().change_scene_to_file()` to change scenes in a multiplayer game.
This often results in synchronization issues, leading to a number of bug reports like the following: https://github.com/godotengine/godot/issues/68407
A workaround is explained in detailed here https://godotengine.org/article/multiplayer-in-godot-4-0-scene-replication/#selecting-levels

I think it'd be important to display this in a way that's not easy to miss, since it goes against user expectations and changing scenes is something almost every Godot project needs to do.

**URL to the documentation page:**
https://docs.godotengine.org/en/stable/tutorials/networking/high_level_multiplayer.html#example-lobby-implementation